My first attempts were to jam a chunk of wood inside, in order to prevent the magazine from collapsing, holding the stamp, then hitting it. That just does not work. In half the cases, I cause the stamp to slide off. Even if not, the resulting indentation is so shallow, that it's essentially unreadable. People used to stamp inspeciton proofs into hardened barrels, and I cannot deal with a thin sheet of metal. So, does anyone know how to do it?